Revert "[dawn][vk] Fix uses of pipeline robustness when robustness is disabled."

This reverts commit 20039ea00f3139d13c5ebe85a11c58f2df21c06b.

Reason for revert: breaks the roll into g3, revert before investigating.

Original change's description:
> [dawn][vk] Fix uses of pipeline robustness when robustness is disabled.
>
> When Dawn's robustness is disabled we use pipeline robustness to tell
> the driver to not do any robustness if it can, so we still need to
> enable the Vulkan extension in that case, to allow passing
> VK_PIPELINE_ROBUSTNESS_BUFFER_BEHAVIOR_DISABLED_EXT.
>
> When robustness is disabled we also need to skip setting the
> VulkanUse*RobustAccess2 toggles since the relevant features are not
> enabled, which would cause a VVL error when they make pipeline
> robustness request "robust access 2".
>
> Fixed: 443940959
> Change-Id: Icb91b2b316b2a543240e5522f9d631862a7cd8a8
> Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/261175
> Reviewed-by: Kyle Charbonneau <kylechar@google.com>
> Commit-Queue: Corentin Wallez <cwallez@chromium.org>
> Reviewed-by: Brandon Jones <bajones@chromium.org>

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: Ibc9175d462fbd840f621b5350c55a0a39cf11acd
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/264694
Commit-Queue: Loko Kung <lokokung@google.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Loko Kung <lokokung@google.com>